The following article is taken from the National Council of Catholic Bishops/United States Catholic Conference website.
The Secretariat of the Bishops' Committee on the Liturgy has received a number of inquiries in the last year concerning the Church's norms governing the use of candles and oil lamps in the liturgy. Many have asked whether oil lamps may be used as substitutes for candles during the celebration of the liturgy. The last time this question was
addressed the by Secretariat was in the June-July 1974 edition of this Newsletter.
The General Instruction of the Roman Missal (GIRM) states the following with regard to the use of candles:
"Candles are to be used at every liturgical service as a sign of reverence and festiveness" (no. 269; see also no. 79).
In a 1974 interpretation of GIRM 269, the Congregation for Divine Worship noted that the GIRM makes no further determination regarding the material of which candles are made except in the case of the sanctuary lamp, the fuel for which must be oil or wax. The Congregation then went on to recall the faculty that the conferences of bishops possess to choose suitable materials.
Since the National Conference of Catholic Bishops has never employed the above-noted faculty to permit the use of materials other than wax in the production of candles, the use of such other materials either as a substitute for or in imitation of candles is not permitted in the liturgy. Therefore, oil lamps may be used only "in the case of the sanctuary lamp," as indicated above. Candles made of wax are to be used in the celebration of the Mass and other liturgical rites. Furthermore, because of their very nature, imitations of candles should not be used in the liturgy as, for example, "permanent" paschal candles, nor should electric bulbs be used in liturgical celebration. In the interests of authenticity and symbolism, it is likewise unfitting that so-called electric vigil lights be used for devotional purposes.